The Within-Subject Association of Physical Behavior and Affective Well-Being in Everyday Life: A Systematic Literature Review.

BACKGROUND: The interplay of physical activity (PA) with affective well-being (AWB) is highly critical to both health behaviors and health outcomes. Current prominent theories presume AWB to be crucial for PA maintenance, and PA is evidenced to foster mental health. However, thus far, PA-AWB associations have mainly been researched in laboratory settings and with interventional designs, but the everyday life perspective had not been focused on, mostly due to technological limitations. In the course of digitization, the number of studies using device-based methods to research the within-subject association of physical activity and affective well-being (PA-AWB) under ecological valid conditions increased rapidly, but a recent comprehensive systematic review of evidence across populations, age groups, and distinct AWB components remained inconclusive. OBJECTIVES: Therefore, we aimed to firstly review daily-life studies that assessed intensive longitudinal device-based (e.g., electronic smartphone diaries and accelerometry) and real-time PA-AWB data, secondly to develop and apply a quality assessment tool applicable to those studies, and thirdly to discuss findings and draw implications for research and practice. METHODS: To this end, the literature was searched in three databases (Web of Science, PubMed, Scopus) up to November 2022. The systematic review followed the PRISMA guidelines and had been pre-registered (PROSPERO id: CRD42021277327). A modified quality assessment tool was developed to illustrate the risk of bias of included studies. RESULTS: The review of findings showed that, in general, already short PA bouts in everyday life, which clearly differ from structured exercise sessions, are positively associated with AWB. In particular, feelings of energy relate to incidental (non-exercise and unstructured) activity, and PA-AWB associations depend on population characteristics. The quality assessment revealed overall moderate study quality; however, the methods applied were largely heterogeneous between investigations. Overall, the reviewed evidence on PA-AWB associations in everyday life is ambiguous; for example, no clear patterns of directions and strengths of PA-AWB relationships depending on PA and AWB components (such as intensity, emotions, affect, mood) emerged. CONCLUSIONS: The reviewed evidence can fuel discussions on whether the World Health Organization's notion "every move counts" may be extended to everyday life AWB. Concurrently, the PA-AWB relationship findings endorse prominent theories highlighting the critical role of AWB in everyday PA engagement and maintenance. However, the review also clearly highlights the need to advance and harmonize methodological approaches for more fine-grained investigations on which specific PA/AWB characteristics, contextual factors, and biological determinants underly PA-AWB associations in everyday life. This will enable the field to tackle pressing challenges such as the issue of causality of PA-AWB associations, which will help to shape and refine existing theories to ultimately predict and improve health behavior, thereby feeding into precision medicine approaches.

Effectiveness of an 11-week exercise intervention for patients with hip or knee osteoarthritis: results of a quasi-experimental pragmatic trial.

OBJECTIVE: To assess the effectiveness of exercise and education in addition to standard care (SC) compared to SC alone in patients with hip or knee osteoarthritis (OA) during 24 months follow-up. DESIGN: We conducted a quasi-experimental pragmatic clinical trial in care centers of a health insurance company. Overall, 1,030 subjects with hip and/or knee OA were included. The intervention group was recruited from clients participating in a hip/knee training (HKT, n = 515) in addition to SC. The control group (CO, n = 515) receiving SC only was recruited from the insurance database. HKT comprised 8 group sessions (1/week) of exercise and education, complemented by a 11-week structured home-exercise program (2/week). Primary endpoints were change of joint-related pain and function (WOMAC Index, score 0-10) after 3 months. Secondary endpoints related to follow-ups at 6, 12 and 24 months. All patient reported outcome measures were analyzed using linear mixed models (LMMs) investigating a time x treatment effect. A multivariable cox proportional hazards regression model was used to identify differences of joint replacement during follow-up between groups. RESULTS: LMMs revealed statistically significant differences in favor of HKT for the primary outcomes WOMAC pain = 0.47 (CI 0.27-0.66; Effect Size (ES) = 0.22, p < 0.001) and WOMAC function = 0.27 (CI 0.11-0.44; ES = 0.13, p < 0.001). HKT was superior to CO for 6, 12, and 24 months as well (ES < 0.2, p ≤ 0.006). HKT was inferior regarding the first incidence of hip or knee AJR during follow-up in comparison to CO (adjusted hazard ratio, HR = 1.57; CI 1.08-2.30; p = 0.020). CONCLUSIONS: This trial demonstrated short-, mid- and long-term superiority of exercise versus control. However, differences were smaller than those reported in previous efficacy trials, raising questions regarding clinical importance. Responder analysis will follow to identify possible predictors for patient responsiveness on an individual level. Further studies should investigate the frequency and reasons for joint replacement following exercise therapy. TRIAL REGISTRATION: German Clinical Trial Register (DRKS00009251). Registered 10 September 2015.

Daily patterns of fatigue after subarachnoid haemorrhage: an ecological momentary assessment study.

OBJECTIVE: To examine the daily course of, and factors associated with, momentary fatigue after subarachnoid haemorrhage, and to explore subgroups of patients with distinct diurnal patterns of fatigue. DESIGN: Observational study using ecological momentary assessment. SUBJECTS: A total of 41 participants with subarachnoid haemorrhage. METHODS: Patients with fatigue were included within one year post-onset. Momentary fatigue (scale 1-7) was assessed with repeated measurements (10-11 times/day) during 7 consecutive days. Multilevel-mixed-model analyses and latent-class trajectory modelling were conducted. RESULTS: Mean (standard deviation; SD) age of the group was 53.9 (13.0) years, 56% female, and mean (SD) time post-subarachnoid haemorrhage onset was 9.3 (3.2) months. Mean (SD) momentary fatigue over all days was 3.22 (1.47). Fatigue increased significantly (p < 0.001) over the day, and experiencing more burden of fatigue and day type (working day vs weekend day) were significantly (p < 0.05) associated with higher momentary fatigue. Three subgroups could be distinguished based on diurnal patterns of fatigue. The largest group (n = 17, 41.5%) showed an increasing daily pattern of fatigue. CONCLUSION: Momentary fatigue in patients with subarachnoid haemorrhage increases over the day, and diurnal patterns of fatigue differ between  participants. In addition to conventional measures, momentary measures of fatigue might provide valuable information for physicians to optimize personalized management of fatigue after subarachnoid haemorrhage.

Unraveling the interplay between daily life fatigue and physical activity after subarachnoid hemorrhage: an ecological momentary assessment and accelerometry study.

BACKGROUND: Fatigue is one of the most commonly reported symptoms after subarachnoid hemorrhage (SAH) and is indirectly associated with physical activity (PA). Associations between fatigue and PA are primarily examined based on conventional measures (i.e. a single fatigue score or average PA levels), thereby assuming that fatigue and PA do not fluctuate over time. However, levels of fatigue and PA may not be stable and may interrelate dynamically in daily life. Insight in direct relationships between fatigue and PA in daily life, could add to the development of personalized rehabilitation strategies. Therefore we aimed to examine bidirectional relationships between momentary fatigue and PA in people with SAH. METHODS: People (n = 38) with SAH who suffer from chronic fatigue were included in an observational study using Ecological Momentary Assessment (EMA) and accelerometry. Momentary fatigue was assessed on a scale from 1 to 7 (no to extreme fatigue), assessed with 10-11 prompts per day for 7 consecutive days using EMA with a mobile phone. PA was continuously measured during this 7-day period with a thigh-worn Activ8 accelerometer and expressed as total minutes of standing, walking, running and cycling in a period of 45 min before and after a momentary fatigue prompt. Multilevel mixed model analyses including random effects were conducted. RESULTS: Mean age was 53.2 years (SD = 13.4), 58% female, and mean time post SAH onset was 9.5 months (SD = 2.1). Multilevel analyses with only time effects to predict fatigue and PA revealed that fatigue significantly (p < 0.001) increased over the day and PA significantly (p < 0.001) decreased. In addition, more PA was significantly associated with higher subsequent fatigue (ß = 0.004, p < 0.05) and higher fatigue was significantly associated with less subsequent PA (ß=-0.736, p < 0.05). Moreover, these associations significantly differed between participants (p < 0.001). CONCLUSIONS: By combining EMA measures of fatigue with accelerometer-based PA we found that fatigue and PA are bidirectionally associated. In addition, these associations differ among participants. Given these different bidirectional associations, rehabilitation aimed at reducing fatigue should comprise personalized strategies to improve both fatigue and PA simultaneously, for example by combining exercise therapy with cognitive behavioral and/or energy management therapy.

Momentary within-subject associations of affective states and physical behavior are moderated by weather conditions in real life: an ambulatory assessment study.

BACKGROUND: Physical behavior (PB) is a key lifestyle factor in regulating and preventing diseases across the lifespan. Researchers identified affective, cognitive, and contextual factors like weather conditions, as significant contributors in determining if individuals are physically active. However, there is scarce empirical evidence about potential associations between PB and affective states influenced by weather conditions in daily life. Therefore, we explored if weather conditions moderated the within-subject association between momentary affective states and subsequent PB. METHODS: Utilizing ambulatory assessment, 79 participants completed electronic diaries about their affective states (i.e., valence, energetic arousal, and calmness) up to six times a day over five days, and their PB (i.e., physical activity and sedentariness) was simultaneously recorded via accelerometers. Weather conditions (i.e., temperature and precipitation) recorded near participants' locations served as moderators in the multilevel analyses. RESULTS: We confirmed earlier findings associating affective states with PB. Increased valence and energetic arousal were positively associated with physical activity (ß = 0.007; p < .001), whereas calmness predicted lower levels of physical activity (ß = -0.006; p < .001). Higher levels of calmness showed a positive association with sedentary behavior (ß = 0.054; p = .003). In addition, we revealed a significant positive association between temperature, as a momentary weather condition, and physical activity (ß = 0.025; p = .015). Furthermore, we showed that the association of affective states and physical activity was moderated by temperature. Higher temperatures enhanced the positive effects of valence on physical activity (ß = .001, p = .023) and attenuated the negative effects of calmness on physical activity (ß = .001, p = .021). Moreover, higher temperatures enhanced the positive effects of valence on reduced sedentary behavior (ß = -0.011, p = .043). CONCLUSIONS: Temperature alterations appeared to have an impact on subsequent physical activity. Furthermore, temperature alterations moderated the influence of affective states on conducted physical activity. This might offer the opportunity for just-in-time adaptive interventions to intervene in individually appropriate environmental conditions for promoting physical activity.

Insights on physical behavior while working from home: An ecological momentary assessment study.

Ever since the COVID-19 pandemic, working from home (WFH) has emerged as a common alternative work environment, but the possible influence on daily physical behavior (PB) (i.e., physical activity (PA), sedentary behavior (SB)) remains unclear. This study aimed to examine daily associations between PB and the work environment (i.e., WFH, working at the office (WAO)), as well as to explore and identify patterns of PB within each work environment. An observational study using a dual-accelerometer system to continuously assess PB for at least 5 days was conducted. The sample consisted of 55 participants providing 276 days of assessment. Additional demographic, contextual, and psychological variables were measured via baseline questionnaire and several smartphone prompts per day. To analyze the effects of the work environment on PB, multilevel analyses were conducted. For the identification of patterns within each work environment, latent class trajectory modelling was applied. Associations between the work environment and various PA parameters were found, indicating that WFH has a negative effect on MVPA time, steps, and physical activity intensity (MET), but a positive effect on short PA bouts (≤5 min). No associations between the work environment and any SB parameter (i.e., SB time, SB breaks, SB bouts) were found. Latent class trajectory modelling revealed three MVPA patterns for days WFH, and two patterns for days WAO. Given the growing prevalence of WFH and the positive health effects associated with MVPA, daily-tailored solutions to enhance MPVA while WFH are urgently needed.

Assessment of 24-hour physical behaviour in adults via wearables: a systematic review of validation studies under laboratory conditions.

BACKGROUND: Wearable technology is used by consumers and researchers worldwide for continuous activity monitoring in daily life. Results of high-quality laboratory-based validation studies enable us to make a guided decision on which study to rely on and which device to use. However, reviews in adults that focus on the quality of existing laboratory studies are missing. METHODS: We conducted a systematic review of wearable validation studies with adults. Eligibility criteria were: (i) study under laboratory conditions with humans (age ≥ 18 years); (ii) validated device outcome must belong to one dimension of the 24-hour physical behavior construct (i.e., intensity, posture/activity type, and biological state); (iii) study protocol must include a criterion measure; (iv) study had to be published in a peer-reviewed English language journal. Studies were identified via a systematic search in five electronic databases as well as back- and forward citation searches. The risk of bias was assessed based on the QUADAS-2 tool with eight signaling questions. RESULTS: Out of 13,285 unique search results, 545 published articles between 1994 and 2022 were included. Most studies (73.8% (N = 420)) validated an intensity measure outcome such as energy expenditure; only 14% (N = 80) and 12.2% (N = 70) of studies validated biological state or posture/activity type outcomes, respectively. Most protocols validated wearables in healthy adults between 18 and 65 years. Most wearables were only validated once. Further, we identified six wearables (i.e., ActiGraph GT3X+, ActiGraph GT9X, Apple Watch 2, Axivity AX3, Fitbit Charge 2, Fitbit, and GENEActiv) that had been used to validate outcomes from all three dimensions, but none of them were consistently ranked with moderate to high validity. Risk of bias assessment resulted in 4.4% (N = 24) of all studies being classified as "low risk", while 16.5% (N = 90) were classified as "some concerns" and 79.1% (N = 431) as "high risk". CONCLUSION: Laboratory validation studies of wearables assessing physical behaviour in adults are characterized by low methodological quality, large variability in design, and a focus on intensity. Future research should more strongly aim at all components of the 24-hour physical behaviour construct, and strive for standardized protocols embedded in a validation framework.

Quality Evaluation of Free-living Validation Studies for the Assessment of 24-Hour Physical Behavior in Adults via Wearables: Systematic Review.

BACKGROUND: Wearable technology is a leading fitness trend in the growing commercial industry and an established method for collecting 24-hour physical behavior data in research studies. High-quality free-living validation studies are required to enable both researchers and consumers to make guided decisions on which study to rely on and which device to use. However, reviews focusing on the quality of free-living validation studies in adults are lacking. OBJECTIVE: This study aimed to raise researchers' and consumers' attention to the quality of published validation protocols while aiming to identify and compare specific consistencies or inconsistencies between protocols. We aimed to provide a comprehensive and historical overview of which wearable devices have been validated for which purpose and whether they show promise for use in further studies. METHODS: Peer-reviewed validation studies from electronic databases, as well as backward and forward citation searches (1970 to July 2021), with the following, required indicators were included: protocol must include real-life conditions, outcome must belong to one dimension of the 24-hour physical behavior construct (intensity, posture or activity type, and biological state), the protocol must include a criterion measure, and study results must be published in English-language journals. The risk of bias was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool with 9 questions separated into 4 domains (patient selection or study design, index measure, criterion measure, and flow and time). RESULTS: Of the 13,285 unique search results, 222 (1.67%) articles were included. Most studies (153/237, 64.6%) validated an intensity measure outcome such as energy expenditure. However, only 19.8% (47/237) validated biological state and 15.6% (37/237) validated posture or activity-type outcomes. Across all studies, 163 different wearables were identified. Of these, 58.9% (96/163) were validated only once. ActiGraph GT3X/GT3X+ (36/163, 22.1%), Fitbit Flex (20/163, 12.3%), and ActivPAL (12/163, 7.4%) were used most often in the included studies. The percentage of participants meeting the quality criteria ranged from 38.8% (92/237) to 92.4% (219/237). On the basis of our classification tree to evaluate the overall study quality, 4.6% (11/237) of studies were classified as low risk. Furthermore, 16% (38/237) of studies were classified as having some concerns, and 72.9% (173/237) of studies were classified as high risk. CONCLUSIONS: Overall, free-living validation studies of wearables are characterized by low methodological quality, large variability in design, and focus on intensity. Future research should strongly aim at biological state and posture or activity outcomes and strive for standardized protocols embedded in a validation framework. Standardized protocols for free-living validation embedded in a framework are urgently needed to inform and guide stakeholders (eg, manufacturers, scientists, and consumers) in selecting wearables for self-tracking purposes, applying wearables in health studies, and fostering innovation to achieve improved validity.

Assessment of 24-hour physical behaviour in children and adolescents via wearables: a systematic review of free-living validation studies.

Objectives: Studies that assess all three dimensions of the integrative 24-hour physical behaviour (PB) construct, namely, intensity, posture/activity type and biological state, are on the rise. However, reviews on validation studies that cover intensity, posture/activity type and biological state assessed via wearables are missing. Design: Systematic review. The risk of bias was evaluated by using the QUADAS-2 tool with nine signalling questions separated into four domains (ie, patient selection/study design, index measure, criterion measure, flow and time). Data sources: Peer-reviewed validation studies from electronic databases as well as backward and forward citation searches (1970-July 2021). Eligibility criteria for selecting studies: Wearable validation studies with children and adolescents (age <18 years). Required indicators: (1) study protocol must include real-life conditions; (2) validated device outcome must belong to one dimension of the 24-hour PB construct; (3) the study protocol must include a criterion measure; (4) study results must be published in peer-reviewed English language journals. Results: Out of 13 285 unique search results, 76 articles with 51 different wearables were included and reviewed. Most studies (68.4%) validated an intensity measure outcome such as energy expenditure, but only 15.9% of studies validated biological state outcomes, while 15.8% of studies validated posture/activity type outcomes. We identified six wearables that had been used to validate outcomes from two different dimensions and only two wearables (ie, ActiGraph GT1M and ActiGraph GT3X+) that validated outcomes from all three dimensions. The percentage of studies meeting a given quality criterion ranged from 44.7% to 92.1%. Only 18 studies were classified as 'low risk' or 'some concerns'. Summary: Validation studies on biological state and posture/activity outcomes are rare in children and adolescents. Most studies did not meet published quality principles. Standardised protocols embedded in a validation framework are needed. PROSPERO registration number: CRD42021230894.

The dynamical association between physical activity and affect in the daily life of individuals with ADHD.

Exercise interventions in mental disorders have evidenced a mood-enhancing effect. However, the association between physical activity and affect in everyday life has not been investigated in adult individuals with ADHD, despite being important features of this disorder. As physical activity and affect are dynamic processes in nature, assessing those in everyday life with e-diaries and wearables, has become the gold standard. Thus, we used an mHealth approach to prospectively assess physical activity and affect processes in individuals with ADHD and controls aged 14-45 years. Participants wore accelerometers across a four-day period and reported their affect via e-diaries twelve times daily. We used multilevel models to identify the within-subject effects of physical activity on positive and negative affect. We split our sample into three groups: 1. individuals with ADHD who were predominantly inattentive (n = 48), 2. individuals with ADHD having a combined presentation (i.e., being inattentive and hyperactive; n = 95), and 3. controls (n = 42). Our analyses revealed a significant cross-level interaction (F(2, 135.072)=5.733, p = 0.004) of physical activity and group on positive affect. In details, all groups showed a positive association between physical activity and positive affect. Individuals with a combined presentation significantly showed the steepest slope of physical activity on positive affect (slope_inattentive=0.005, p<0.001; slope_combined=0.009, p<0.001; slope_controls=0.004, p = 0.008). Our analyses on negative affect revealed a negative association only in the individuals with a combined presentation (slope=-0.003; p = 0.001). Whether this specifically pronounced association in individuals being more hyperactive might be a mechanism reinforcing hyperactivity needs to be empirically clarified in future studies.

The context matters - not all prolonged sitting bouts are equally related to momentary affective states: an ambulatory assessment with sedentary-triggered E-diaries.

BACKGROUND: Sedentary behaviors (SB) and especially prolonged sitting bouts are highly prevalent in daily life and studies indicated an association with an increased risk for several non-communicable diseases. Consequently, guidelines to reduce SB were developed. At the same time, an in-depth knowledge regarding SB such as where, what and with whom people spend time sedentary as well as correlates such as affective states of prolonged sitting bouts, is still lacking. A more differentiated view on SB is necessary to identify detrimental and modifiable sedentary bouts. We addressed this gap by conducting an ambulatory assessment study including accelerometer and sedentary-triggered e-diaries that captures data during prolonged sitting bouts (> 20 min). We investigated how contextual factors of prolonged sitting bouts are associated with momentary affective states. METHOD: Four studies were combined with a final sample of 308 participants (50.3% female, Mage, 27.4, range, 17-66). SB was assessed objectively with thigh-worn accelerometers for four to five days. Whenever a participant was sitting for 20 or 30 min the accelerometer triggered questions assessing social (not alone vs. alone) and environmental (leisure vs. working) factors as well as momentary affective states (valence, energetic arousal and calmness). Multilevel analyses were used to examine within-person associations between different contexts and mood during prolonged sitting. RESULTS: Momentary affective states varied significantly due to different social and environmental contexts (ps < 0.001): Sitting together with others was associated with higher levels of valence and energetic arousal. Furthermore, sitting during leisure time was associated with higher levels of valence and calmness and lower levels of energetic arousal. Significant interaction analyses revealed that participants had the highest ratings while sitting during leisure episodes together with others. CONCLUSION: Findings showed that prolonged sitting bouts differ regarding their association with affect. Sitting with others, sitting during leisure time and especially sitting during leisure time and with others, was associated with higher levels of momentary affective states, respectively. Thus, SB guidelines should focus on reducing those SB episodes that are associated with lower levels of affect, for example during working episodes.

Drivers of productivity: Being physically active increases yet sedentary bouts and lack of sleep decrease work ability.

Physical behavior (ie, physical activity, sedentary behavior, and sleep) is a crucial lifestyle factor for preventing and managing diseases across the lifespan. However, less is known about potential work-related psychological and cognitive outcomes such as productivity. The present study examined within-person associations between physical behavior and self-perceived work ability. To investigate the degree to which physical behavior parameters influence self-perceived work ability in everyday life, we conducted an Ambulatory Assessment study in 103 university students over 5 days. Physical behavior was assessed continuously via a multi-sensor system. Self-perceived work ability was assessed repeatedly up to six times per day on smartphones. We employed multilevel modeling to analyze the within-person effects of physical behavior on self-perceived work ability. Physical activity intensity (MET) (ß = 0.15 ± 0.06, t = 2.59, p = 0.012) and sit-to-stand transitions (ß = 0.07 ± 0.03, t = 2.44, p = 0.015) were positively associated with self-perceived work ability. Sedentary bouts (≥20 min) (ß = -0.21 ± 0.08, t = -2.74, p = 0.006) and deviation from a recommended sleep duration (ie, 8 h) (ß = -0.1 ± 0.04, t = -2.38, p = 0.018) were negatively associated with self-perceived work ability. Exploratory analyses supported the robustness of our findings by comparing various time frames. Total sedentary time and sleep quality were not associated with self-perceived work ability. Regular sleep durations, breaking up sedentary time through sit-to-stand transitions, and higher intensities of physical activity may be important for the regulation of self-perceived work ability in university students' daily lives.

A neural mechanism for affective well-being: Subgenual cingulate cortex mediates real-life effects of nonexercise activity on energy.

Physical activity substantially improves well-being and mental health, but the underlying brain processes remain unclear. Most research concerns exercise, although the majority of everyday human behaviors, such as walking or stair climbing, are nonexercise activities. Combining neuroimaging with ecological assessment of activity and GPS-triggered smartphone diaries, we show a specific association of nonexercise activity with energy in two independent samples mediated by the subgenual part of the anterior cingulate cortex (sgACC), a key emotion regulatory site. Furthermore, energy predicted a range of mental health metrics. sgACC volume moderated humans' emotional gain from nonexercise activity in real life: Individuals with low sgACC volume, a risk factor for depression, felt less energized when inactive but benefited more from periods of high nonexercise activity. This suggests an everyday life mechanism affecting affective well-being in the general population and, if substantiated in patient samples, a risk and resilience process for mood disorders.

Accuracy of Sedentary Behavior-Triggered Ecological Momentary Assessment for Collecting Contextual Information: Development and Feasibility Study.

BACKGROUND: Sedentary behavior has received much attention in the scientific community over the past decade. There is growing evidence that sedentary behavior is negatively associated with physical and mental health. However, an in-depth understanding of the social and environmental context of sedentary behavior is missing. Information about sedentary behavior, such as how everyday sedentary behavior occurs throughout the day (eg, number and length of sedentary bouts), where, when, and with whom it takes place, and what people are doing while being sedentary, is useful to inform the development of interventions aimed at reducing sedentary time. However, examining everyday sedentary behavior requires specific methods. OBJECTIVE: The purpose of this paper is (1) to introduce sedentary behavior-triggered Ecological Momentary Assessment (EMA) as a methodological advancement in the field of sedentary behavior research and (2) to examine the accuracy of sedentary behavior-triggered EMA in 3 different studies in healthy adults. Moreover, we compare the accuracy of sedentary behavior-triggered EMA to simulations of random-trigger designs. METHODS: Sedentary behavior-triggered EMA comprises a continuous assessment of sedentary behavior via accelerometers and repeated contextual assessments via electronic diaries (ie, an application on a smartphone). More specifically, the accelerometer analyzes and transfers data regarding body position (a sitting or lying position, or an upright position) via Bluetooth Low Energy (BLE) to a smartphone in real time and triggers the deployment of questionnaires. Each time a participant spends a specified time (eg, 20 minutes) in a sedentary position, the e-diary triggers contextual assessments. To test the accuracy of this method, we calculated a percentage score for all triggered prompts in relation to the total number of bouts that could trigger a prompt. RESULTS: Based on the accelerometer recordings, 29.3% (5062/17278) of all sedentary bouts were classified as moderate-to-long (20-40 minutes) and long bouts (≥ 41 minutes). On average, the accuracy by participant was 82.77% (3339/4034; SD 21.01%, range 71.00-88.22%) on the study level. Compared to simulations of random prompts (every 120 minutes), the number of triggered prompts was up to 47.9% (n=704) higher through the sedentary behavior-triggered EMA approach. Nearly 40% (799/2001) of all prolonged sedentary bouts (≥ 20 minutes) occurred during work, and in 57% (1140/2001) of all bouts, the participants were not alone. CONCLUSIONS: Sedentary behavior-triggered EMA is an accurate method for collecting contextual information on sedentary behavior in daily life. Given the growing interest in sedentary behavior research, this sophisticated approach offers a real advancement as it can be used to collect social and environmental contextual information or to unravel dynamic associations. Furthermore, it can be modified to develop sedentary behavior-triggered mHealth interventions.

[Control group formation using propensity score matching: The role of primary and secondary data - Results of prevention studies]. / Kontrollgruppenbildung durch Propensity-Score-Matching: Die Rolle von Primär- und Sekundärdaten − Ergebnisse aus Präventionsstudien.

BACKGROUND: The creation of control groups in the evaluation of statutory health insurances is a key issue. Randomization represents both an ethical and a legal problem with legally guaranteed services. Matching procedures are relevant alternatives in the construction of control groups. Matchings are mostly based on secondary data from statutory health insurances (for example age, gender, cost of illness, days of incapacity to work). In this study, we examined whether matching based on secondary data alone can cause selection bias. METHODS: We used data from three large prevention studies and applied sensitivity analyses to compare the results of propensity score matchings used to create control groups on the basis of secondary data, with those obtained on the basis of both primary and secondary data. Analysis of covariance was used to investigate the impact of potential selection bias on cost effects. RESULTS: Matchings based on secondary data alone lead to control groups with similar characteristics captured by secondary data. However, the control group participants are significantly healthier (they have, for example, lower levels of pain, lower levels of psychological stress, a higher degree of quality of life) than the patients in intervention groups. This selection bias would lead to a systematic underestimation of the cost reduction produced by preventive interventions. DISCUSSION: Prevention course participants seem to have characteristics that differ from the average population (higher health orientation level, preference for prevention over medical treatment services, etc.) and cannot be captured by secondary data; therefore, matchings based on secondary data alone cause selection bias. CONCLUSIONS: Including both primary and secondary data reduces the risk of selection bias in matching procedures for prevention studies. The E-value can be used to evaluate the robustness of results with regard to selection bias.

Ambulatory Assessment for Physical Activity Research: State of the Science, Best Practices and Future Directions.

Technological and digital progress benefits physical activity (PA) research. Here we compiled expert knowledge on how Ambulatory Assessment (AA) is utilized to advance PA research, i.e., we present results of the 2nd International CAPA Workshop 2019 "Physical Activity Assessment - State of the Science, Best Practices, Future Directions" where invited researchers with experience in PA assessment, evaluation, technology and application participated. First, we provide readers with the state of the AA science, then we give best practice recommendations on how to measure PA via AA and shed light on methodological frontiers, and we furthermore discuss future directions. AA encompasses a class of methods that allows the study of PA and its behavioral, biological and physiological correlates as they unfold in everyday life. AA includes monitoring of movement (e.g., via accelerometry), physiological function (e.g., via mobile electrocardiogram), contextual information (e.g., via geolocation-tracking), and ecological momentary assessment (EMA; e.g., electronic diaries) to capture self-reported information. The strengths of AA are data assessment that near realtime, which minimizes retrospective biases in real-world settings, consequentially enabling ecological valid findings. Importantly, AA enables multiple assessments across time within subjects resulting in intensive longitudinal data (ILD), which allows unraveling within-person determinants of PA in everyday life. In this paper, we show how AA methods such as triggered e-diaries and geolocation-tracking can be used to measure PA and its correlates, and furthermore how these findings may translate into real-life interventions. In sum, AA provides numerous possibilities for PA research, especially the opportunity to tackle within- subject antecedents, concomitants, and consequences of PA as they unfold in everyday life. In-depth insights on determinants of PA could help us design and deliver impactful interventions in real-world contexts, thus enabling us to solve critical health issues in the 21st century such as insufficient PA and high levels of sedentary behavior.

How effective and efficient are different exercise patterns in reducing back pain?

BACKGROUND: Exercise is considered an effective intervention to relieve chronic back pain. However, it is still unknown whether specific exercise patterns vary in terms of their efficiency and effectiveness. AIM: To investigate the differential health and economic effects of intensity, specificity and degree of subjective perceived physical exertion across five exercise patterns (endurance, gymnastics, fitness, back gymnastics, multimodal back exercise) in adults with back pain. DESIGN: Longitudinal observational cohort study over a period of 24 months. SETTING: Various non-therapeutic exercise facilities (e.g. outdoor, fitness centers, health insurance programs, sports clubs) across one federal state of Germany (Baden-Wuerttemberg). POPULATION: Adults with back pain (N.=2,542, Mean =46.9 years, 66% females, graded chronic back pain [GCPS] 1=40.5%, GCPS 2=27.3%, GCPS 3=20.7%, GCPS 4=11.5%). METHODS: Self-reported back pain (functional restrictions and pain = back pain function score, [BPFS]) and characteristics of exercising behavior (frequency, duration, type, physical exertion) were assessed at baseline and at 6, 12, 18 and 24 months. Direct medical costs for back disorders (international classification of diseases, dorsopathies: M40-M54) were compiled from health insurance records. RESULTS: Moderate- to high-intensity exercise patterns were effective in reducing back pain, particularly at lower levels of subjective perceived physical exertion. At these intensity levels, multimodal back exercise (i.e. exercising the spine-stabilizing muscles specifically, ergonomic training) was 14.5 times more effective than non-back specific fitness exercise in reducing BPFS. The beneficial effects of both exercise types increased with the initial severity of back pain. However, only multimodal back exercise (moderate- to high-intensity/high back specificity) was associated with a significant decrease in direct medical costs for back pain. CONCLUSIONS: Targeted exercise of the spine-stabilizing musculature at moderate to high intensities without maximum perceived exertion is effective and efficient in reducing back pain. CLINICAL REHABILITATION IMPACT: The combination of high-intensity and high-specificity exercises yielded a significant reduction in medical costs. However, the intensities in terms of muscular load in endurance training and gymnastics may not be sufficient to reduce back pain effectively.

Momentary mood predicts upcoming real-life sedentary behavior.

Humans in the industrialized world spend a large amount of daily time in sedentary behavior. Since sedentariness negatively impacts a variety of psychophysiological outcomes, the identification of antecedents that lead to sedentary behavior is an important public health issue. In this context, mood, a central indicator for both psychological well-being and mental health, is severely understudied. To investigate whether mood dimensions influence subsequent sedentary behavior, we assessed both constructs at baseline via questionnaires and via ambulatory assessment (AA) over 5 days in 92 university employees. We continuously measured sedentary behavior using accelerometers and assessed mood repeatedly 10 times each day on smartphone diaries. We employed multiple regression analyses to analyze between-subject effects and multilevel modeling to analyze within-subject effects. Higher momentary ratings of valence (P < .05) and energetic arousal (P < .01) predicted lower amounts of subsequent sedentary behavior, whereas higher ratings of calmness (P < .01) predicted higher amounts of subsequent sedentary behavior. The context moderated the effect of energetic arousal and calmness on sedentary behavior with increased effects in the home compared to the work context. Mood significantly predicted sedentary behavior on a within-subject level but not on a between-subject level. Preliminary evidence suggests that mood regulates sedentary behavior in everyday life. Time-sensitive analyses, such as from moment to moment revealed an association between mood and sedentary behavior (within-subject), whereas analyses between different individuals revealed no associations (between-subject). These preliminary findings may inform multicomponent intervention strategies that target mood, to reduce sedentary behavior in daily life.

Relationships between incidental physical activity, exercise, and sports with subsequent mood in adolescents.

Physical activity is beneficial for human physical health and well-being. Accordingly, the association between physical activity and mood in everyday life has been a subject of several Ambulatory Assessment studies. This mechanism has been studied in children, adults, and the elderly, but neglected in adolescents. It is critical to examine this mechanism in adolescents because adolescence plays a key role in human development and adolescents' physical activity behavior translates into their behavior in adulthood. We investigated adolescents' mood in relation to distinct physical activities: incidental activity such as climbing stairs; exercise activity, such as skating; and sports, such as playing soccer. We equipped 134 adolescents aged 12-17 years with accelerometers and GPS-triggered electronic diaries to use in their everyday life. Adolescents reported on mood repeatedly in real time across 7 days, and these data were analyzed using multilevel-modeling. After incidental activity, adolescents felt better and more energized. After exercise, adolescents felt better but less calm. After sports, adolescents felt less energized. Analyses of the time course of the effects confirmed our findings. Physical activity influences mood in adolescents' everyday life, but has distinct effects depending on the kind of physical activity. Our results suggest incidental and exercise activities entail higher post-bout valence compared to sports in competitive settings. These findings may serve as an important empirical basis for the targeted application of distinct physical activities to foster well-being in adolescence.